WASHINGTON (AP) — Vice President Joe Biden won't be on stage for the first Democratic presidential debate, but he'll be watching from his official residence in Washington.

Biden's office says he'll watch from the Naval Observatory after hosting a high school reunion. In the run-up to the debate, Biden's lack of a decision about entering the race spurred speculation he'd fly to Las Vegas last-minute to debate. Debate host CNN is keeping a podium ready for him just in case.

If Biden tunes in early, he may catch an ad airing nationally urging him to run. Draft Biden says it's spending $250,000 to air the jobs-focused ad ahead of the debate and on Wednesday. The super PAC pulled its first ad about the death of Biden's wife and daughter at his request.